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Hydrovac rebuilders

At one time there was two or three ads in turning wheels from hydrovac rebuilders but I don't see any current ones. Anyone know a reputable rebuilder that I won't have to rob a bank to pay for a rebuild.

At one time there was two or three ads in turning wheels from hydrovac rebuilders but I don't see any current ones. Anyone know a reputable rebuilder that I won't have to rob a bank to pay for a rebuild.

If it is for a Hawk with the booster in front of the battery, Earle, just buy a brand new one from Studebaker International. The market for rebuilding them has dried up since rebuilders can't make much money and try to match Ed Reynold's price of an entirely new unit. BP

We've got to quit saying, "How stupid can you be?" Too many people are taking it as a challenge.

Ayn Rand: "You can avoid reality, but you cannot avoid the consequences of avoiding reality."

G. K. Chesterton: This triangle of truisms, of father, mother, and child, cannot be destroyed; it can only destroy those civilizations which disregard it.

The HydroVac rebuilder in the Portland, Oregon area is Brake Systems Incorporated. They have been in business for a long time and have done many HydroVacs for local Studebaker owners. Also local is Power Brake Booster Exchange, but they do firewall mount (MasterVac) boosters only. So we are fortunate in this area to have both of these rebuilders.

They are simple to rebuild, if you have the parts. I have done them. Usually the leather seals are so shrunk they wont work unless you soak them a long time. There is more than just the vacuum piston seal that is leather. The air actuating diaphragm is paper thin, and also degrades in storage so If you can't find a well stored kit, then replacing is usually better. The slave cylinder rusts and pits just like a master cylinder, and the smaller hydraulic bore that actuates the air valve diaphragm also corrodes because it is aluminum.

Post 12.....or a clogged hill holder. I had the same problem, thought it was the hydrovac. Disconnect brake lines from hill holder, plug them and put a jumper line at hill holder taking it out of the circuit. See if problem disappears.

I have a 63 Hawk with dragging disk brakes. With the engine off there is no dragging, so can I assume that my problem is the hydrovac that was put in last summer?

Unfortunately-no. It may be, or it may be bad front hoses, or it may be bad caliper seals, or it may be bad pad retractors, or as tim333 says it could be the hill holder if so equipped. The pedal rod to master may have changed adjustment and on and on. And easiest fix of all-you may need to flush all the lines, hoses and every part of the brake system to eliminate any moisture from the system. For some reason the smallest amount of moisture, will expand and cause the calipers to not release. I had a link to a Bendix site that went through the diagnostics for a "sticking" hydrovac but can't find it. Try the flush first, and I do mean "flush" including bleeding off fluid in the hydrovac itself, before giving up on the rebuilt. There is a reason they don't use them on cars anymore!!

Bull. They don't use them, because they were designed for single circuit brake systems. People couldn't care less about regular maintenence . They were used in heavy trucks as well as Studebakers. Cadillac even used them. They work good if they are maintained, and if they are assembled right in the first place. (either new or rebuilt)!

Bull. They don't use them, because they were designed for single circuit brake systems. People couldn't care less about regular maintenence . They were used in heavy trucks as well as Studebakers. Cadillac even used them. They work good if they are maintained, and if they are assembled right in the first place. (either new or rebuilt)!

Sorry to disagree, as said "on cars anymore". They work well, as you say, when cared for, but do fail more often than a plain vacuum booster, by virtue of their complexity.

First of all, my thanks to all of you that responded to my call for help.
Thought you would like an update on the dragging front brake solution.
After adjusting the brake pedal linkage, Studebaker International indicated that the problem might be in the flex hoses to the Hydrovac. They said that while they may look good outside, they could be collapsing internally, so ordered two.
At the point of installing the lines to the front disk brakes, it was apparent that these hoses were much shorter than the ones in place, so called SI to confirm installation instructions. No, they were supposed to connect the Hydrovac to the steel lines going to the disk brakes.
Sometime in the history of this hawk someone had installed steel lines where the flex lines were supposed to go, which invalidated the collapsing flex hose theory.
On further inspection of the all the other hoses and attachments to the Hydrovac, discovered a hose clamp to the rear of the Hydrovac connecting Control tube to the Control valve in front of the Hydrovac. The clamp in question was no obviously miss-aligned, just at an angle. Re-seated the hose clamp closer to the rear of the Hydrovac, thus closed off the vacuum leak. Hydrvac System.jpgHydrovac Clamp.jpg
I did not realize that the adjustment of the clamp resolved the problem until I was driving away from the garage, and the disk brakes were not dragging.
BTW, the SI folks were happy to refund the cost of the flex hoses after I returned them.
Thanks again to all you Stude-warriors and your sage advice.